Fodder research embedded in a system of innovation

A 3-year project implemented in India and Nigeria addressed the issue of improving livelihoods of poor livestock keepers by improving availability of fodder. The original approach focused on testing of new crop varieties to be scaled up through partners using mechanisms such as farmer-to-farmer exchange and field days. As the project evolved, it became clearer that the systems were much more complex than originally thought with a wide range of actors involved. Although fodder technology is obviously a requirement to reduce fodder shortages, many of the problems are embedded in the institutions and policies that determine how technology is developed and delivered. To help address these issues, an innovation systems approach is proposed with a focus on building capacity within the system

Advances in cowpea cropping systems research

Cowpea (Vigna unguiculata) [L.] Walp.) is a major component of the traditional cropping systems in Africa, Asia, and Central and South America where it is widely grown in mixtures with other crops in various combinations. The productivity of cowpea in these mixtures is low, mainly due to low plant population, competition under intercropping, and lack of crop protection measures. Studies have shown that the productivity of cowpea in these systems could be enhanced through the use of improved varieties, appropriate date of planting with respect to the cereal, higher plant populations, improved soil fertility, and suitable spatial arrangements. This paper highlights recent research leading to improvements in cowpea cropping systems. These include improved productivity as a result of early cowpea planting, strip cropping, dense planting, and appropriate soil fertility management. For example, in West Africa, the use of high yielding improved varieties in a strip cropping system with two cereal rows : four cowpea rows offers an opportunity for selective input application and appears to be economically superior to the traditional one cereal row: one cowepea row

Effect of crop rotation and nitrogen fertilization on yield and nitrogen efficiency in maize in the northern Guinea savanna of Nigeria

Two crop rotation cycles were evaluated to determine the effect of cropping systems and N fertilization on the yield and efficiency of N in maize. Maize was grown on plots which had previously supported monocrops of two genotypes each of soybean (TGx 1448-2E and SAMSOY-2) and cowpea (IT 96D-724 and SAMPEA-7), natural fallow and maize. In a split-plot experimental design, three N fertilizer rates (30, 60 and 90 kg ha-1) and an unfertilized control were compared. On average, maize following legumes had higher grain yield of 1.2 and 1.3-fold compared with maize after fallow or maize after maize respectively. Similarly, legume rotation resulted in significant increase in total N uptake compared to continuous maize. In both years, N agronomic efficiency (AEN) and N fertilizer recovery efficiency (REN) of maize following grain legumes were on average 14 and 34% greater than of maize following maize and 12 and 20% greater than of maize following fallow respectively. On the other hand, all N efficiency indices except N physiological efficiency significantly decreased with increasing N levels. These indicate greater N use efficiency for the legume-rotation and poor efficiency for maize monoculture as well as the inefficiency of the current method of N fertilizer application

Germination of witchweed [Striga hermonthica (del.) Benth.] seeds in response to stimulation by root exudates of soybean (Glycine max l.)

Using an adaptation of the Cut-root technique, twenty-one varieties of soybean were screened at 10, 15 and 20 days after planting (DAP) for the stimulation of S. hermonthica seed germination. The varieties were TGX1649-11F, TGX1740-7F, TGX1660-15F, TGX1740-2F, TGX1670-3F, TGX1674-3F and SAMSOY-2. Other varieties tested included TGX1681-3F, TGX1479-1E, TGX923-2E, TGX1440-1E, TGX1448-2E, TGX1660-19F, TGX1519-10F, TGX1019-2EN, TGM-344, TGX1019-EB, TGX1485-1D, TGX536-02D, TGM-351 and TGX849-3B. The strigol analogue, GR-24, was used as the control. The germination of S. hermonthica seeds that was stimulated by GR-24 was significantly higher (P≤0.01) than that stimulated by all the soybean varieties at all the periods. The most promising varieties were TGX1681-3F, TGX1479-1 E, TGX1649-11F and SAMSOY-2 with Specific Effectiveness Index (SEI) values of 0.76, 0.75, 0.58 and 0.54, respectively. The other varieties that showed promise include TGX1740-7F, TGX923-2E TGX1440-1 E and TGM344 with SEI values of 0.44, 0.44, 0.45 and 0.44, respectively. There was no relationship between the age of the plant and potency of its root exudates, except for TGX1649-11F, TGM-344 and TGX1681-3F where activity increased with age from 10DAP to 20DAP. These varieties may therefore be used in field crop rotation systems as an option for the management of S hermonthica. Keywords: witchweed, soybean, trapcropping, crop rotation, Striga hermonthica [Global Jnl Agric Res Vol.2(1) 2003: 25-32